The invention relates to a data medium in card form which is produced substantially from plastic, may have metal parts, comprises a large semiconductor memory capacity and, for data transmission, can be externally bonded via electroplated contacts.
An example of data medium systems currently known and in use is that of magnetic tapes, which generally consist of polyester and are covered with a magnetic powder or a magnetizable layer. Many forms which this takes may be mentioned, such as tapes, cassettes, cartridges or else that of the smart card, which consists, for example, of PVC (polyvinylchloride) and may have an impressed structure or a magnetic strip. Furthermore, optical systems are known, such as CD (compact disc; CD-ROM/compact disc; read-only memory). The individual forms may be only readable or readable and also rewritable.
The latest data medium systems comprise one or more semiconductor memory elements. Suitable for this, in particular also for reasons of cost, are commercial random-access memories. These may be designed, for example, as a DRAM (dynamic random-access memory). Today, the most popular type of data medium system, in particular data medium card, is the smart card. Also known are data media for data processing systems (PCMCIA standard), which can be used, for example, on a personal computer for backup as external data media. These comprise a multiplicity of semiconductor elements and may also serve, for example, as a substitute for a hard disc.
In the case of the so-called smart card, in a version as a chip card, and in the case of a memory card, the contact-dependent data transmission is generally performed using electroplated contacts. This constitutes a fundamental difference in comparison with an electronic standard component. A DIL (dual in line) package of a semiconductor chip has entirely different external bonding means than one of the cards mentioned. In the case of a data medium in card form of the abovementioned type, plug contacts are generally used, specially designed according to type and requirements. Firstly, the semiconductor memory elements have to be integrated into the plastic cards, these cards not necessarily having to conform in their dimensions to a standard for chip cards, although it is advisable for them to do so. What is essential is that the required memory capacity of the semiconductor elements in a data medium card is combined with an essential space requirement for such semiconductor memory chips. The data medium systems in the form of a data medium card have, as stated, so-called plug and pull contacts and must correspondingly transfer forces in order that the card can be plugged into or pulled out with the corresponding contacts on a data processing system or on an adapter. Since the relatively large main faces of such a data medium card are to serve essentially for imparting advertising information, it would be important to make the electroplated contacts intrinsically stable, in order not to cause damage to the advertising areas by a transfer of force to the plastic body of the data medium. This must also be seen against the background that, in use, such a card is to withstand as far as possible without any damage a very high number of insertion and removal operations.
Examples of special configurations of electroplated contact connections which may be mentioned at this stage are plug and pull contacts or snap connections, multipoint connectors and terminal strips or the like.
It is evident that the external electrical connection of a semiconductor device takes place in any case via a disconnectable electrical connection. In contrast to this, the standard assembly process of a semiconductor device in conjunction with a leadframe provides a non-disconnectable electrical and mechanical connection of the outer leads. The assembly technique in the case of a chip card cannot be transferred to a data medium of the type described above in as far as the module inserted into a chip card is very small in relation to the size of the data medium card.